ABSTRACT
Anacardium occidentale Linn. (Anacardiaceae) is a plant largely used in Africa for the treatment of different diseases. In Côte d'Ivoire it's commonly used for the treatment of hypertension. The present study was carried out in order to assess the effects of Anacardium occidentale extract (ANOE) on cardiovascular parameters in animal models. A mercury manometer kymograph of Ludwig was used to measure the blood pressure of normotensive rabbits in control conditions (normal physiological solution) and under the influence of ANOE. The contractile activity of an isolated rat heart was also measured in control conditions and under the influence of ANOE in different physiological media using a modified Langendhorff (1895) apparatus. The aqueous Anacardium occidentale (ANOE) bark extract applied intravenously in different doses (12, 40, 90, and 167 mg/kg b.w.), produced a significant dose-dependent decrease in blood pressure of previously normotensive rabbits (up to 89% vs control). Atropine (1 mg/ml) pre-treatment failed to reverse the hypotensive effects elicited by the extract. ANOE applied to isolated rat heart preparations in different concentrations (0.01, 0.1, 1.0, and 10 µg/ml) induced negative inotropic and chronotropic effects. Atropine pre-treatment of heart preparations (0.1 µg/ml) failed to reverse the negative effects induced by ANOE. The extract's action on heart contractile activity studied in modified culture media further confirmed its cardio-inhibitory effects. ANOE induced strong hypotensive and cardio-inhibitory effects in animal models.
Subject(s)
Anacardium , Blood Pressure/drug effects , Heart Rate/drug effects , Hypotension/chemically induced , Myocardial Contraction/drug effects , Plant Extracts , Animals , Depression, Chemical , Dose-Response Relationship, Drug , Hypotension/physiopathology , Injections, Intravenous , Lethal Dose 50 , Models, Animal , Plant Bark , Plant Extracts/isolation & purification , Plant Extracts/pharmacology , Plant Extracts/toxicity , Plant Stems , Rabbits , Rats , Rats, WistarABSTRACT
The ability of Alchornea cordifolia (Schum. and Thonn.) Müll. Arg. (Euphorbiaceae) leaves to inhibit human neutrophil elastase (HNE) and superoxide anion (O(2)(*-)) activities was evaluated on aqueous and ethyl acetate extracts as they allow for a targeted extraction of polyphenols. The direct effect of A. cordifolia extracts on HNE and O(2)(*-) was assessed in an acellular system. Results showed that extracts scavenge HNE and O(2)(*-) in a dose-dependent manner. Better activity was exhibited by the ethyl acetate extract with lower IC(50) (2.2 and 4. 1 mg/L for HNE and O(2)(*-), respectively) than for the aqueous extract. Cellular systems including isolated human polymorphonuclear neutrophils (PMN) were investigated to assess the effect of extracts on PMN metabolism. PMN were stimulated with 4beta-phorbol-12-myristate-13-acetate (PMA), calcium ionophore (CaI), or N-formyl-methionyl-leucine-phenylalanine (fMLP), each stimulant having its own stimulation pathway. From the IC(50) obtained, it can be concluded that A. cordifolia reduces HNE and O(2)(*-) liberation. Furthermore it was demonstrated that A. cordifolia extracts have no cytotoxic activity on PMN by measuring release of the cytosolic enzyme lactate dehydrogenase. As the ethyl acetate extract offers a higher rate of total phenols than the aqueous extract as well as better scavenging activity, it can be supposed that polyphenols, which are well known for their potent antioxidant and antielastase activity, are implicated in the activity of the plant. Phenolic substances such as quercetin, myricetin-3-glucopyranoside, myricetin-3-rhamnopyranoside, and proanthocyanidin A2 were identified in the ethyl acetate extract. In conclusion, the study provides proof of ethnomedical claims and partly explains the mechanisms of the anti-inflammatory action of A. cordifolia leaves.
